How Does a Dynamic Microphone Work?
Updated Nov 13, 2026 · By 
Jonah Mercer · Editorial policy
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A dynamic microphone works by turning sound into electricity with a moving coil. Sound waves move a thin diaphragm, the diaphragm moves a coil of wire inside a magnetic field, and that motion creates the electrical signal your interface or mixer records. No outside power is needed, and the microphone connects with an XLR cable.
Sound moves a diaphragm and a coil
Inside a dynamic microphone, sound waves push on a thin diaphragm, and the diaphragm carries a coil of wire that sits inside a magnetic field. As the diaphragm moves, the coil moves with it, and the motion of the coil in the field creates a small electrical signal that follows the sound. The signal leaves the microphone through an XLR cable to your interface, mixer or recorder. Nothing in the microphone needs outside power to make that signal.
No outside power is needed
A dynamic microphone makes its own signal, so it does not need 48V phantom power. Condenser microphones need 48V to work, and a standard dynamic microphone is not affected when phantom power is on. Plug the microphone into an XLR input, and leave 48V off unless a condenser microphone on that input needs it. The SM7dB in this guide has a built-in preamp, which adds gain inside the microphone rather than needing a separate inline preamp.
The polar pattern shapes what it hears
The polar pattern is the shape of what the microphone hears. A cardioid pattern picks up sound mainly from the front and less from the sides and rear, which keeps room noise and reflections lower in the recording. The SM7dB, the SL40X and the PodMic in this guide are cardioid. A hypercardioid pattern is narrower still, and the AT2040 in this guide lists a hypercardioid pattern that reduces pickup from the sides and rear for vocal isolation.
Mounts and windscreens clean up the sound
Knocks, bumps and plosives reach the microphone through the stand and the air, so makers add parts to tame them. The AT2040 has an integrated shock mount and a multistage windscreen for pop filtering, the PodMic has an internal shock mount and a built-in pop filter, and the SM7dB has air suspension shock isolation with a detachable windscreen. These parts sit inside or around the microphone body, so they work without any extra gear. Keep the microphone on a stable stand or boom, and speak across the microphone rather than straight into it.
Gain and tone controls shape the output
The signal from a dynamic microphone is weak, so it needs gain at the interface or mixer. The SM7dB gives +18 dB or +28 dB of clean onboard gain from its built-in preamp, and its rear-panel EQ switches shape bass roll-off and mid-range presence. The FDUCE SL40X connects to interfaces and mixers through its XLR cable, and its 2m cable is included in the box. Set the gain so your voice sits clearly above the room, and raise it in small steps until the level is right.
What you need
Audio-Technica AT2040 Hypercardioid Dynamic Podcast Microphone Hypercardioid
A hypercardioid dynamic microphone with a large diaphragm, a multistage windscreen and an integrated shock mount, with an XLR output and a pivoting stand mount.
- XLR output
- Polar pattern: Hypercardioid
- 2-year warranty stated
Shure SM7dB Dynamic Vocal Mic with Preamp
A cardioid dynamic vocal microphone with a built-in preamp giving +18 dB or +28 dB of gain, rear-panel EQ switches and an XLR output.
- XLR output
- Polar pattern: Cardioid
- 2-year warranty stated
FDUCE SL40X XLR Dynamic Podcast Microphone
A cardioid dynamic microphone with an all-metal body, a 50-14000 Hz response range and a 2m XLR cable in the box, with an XLR output.
- XLR output
- Polar pattern: Cardioid
- 1-year warranty stated
- 1 lb, the lightest here
Rode RØDE PodMic Cardioid Dynamic Broadcast Microphone
A cardioid dynamic broadcast microphone with an internal pop filter and shock mount, a yoke mount with 3/8 and 5/8 inch threads, and an XLR output.
- XLR output
- Polar pattern: Cardioid
- 2-year warranty stated
These come from our ranked list Best Dynamic Microphone, which compares them spec by spec.
Frequently asked questions
Does a dynamic microphone need phantom power?
No. A dynamic microphone makes its own signal and does not need 48V phantom power. Only condenser microphones need it, so leave 48V off for a dynamic mic.
Why is a dynamic microphone good for podcasting?
Its cardioid pattern picks up the voice in front of it and less of the room around it. The AT2040 lists a hypercardioid pattern that cuts pickup from the sides and rear, and the SM7dB lists a cardioid pattern with shock isolation.
What is the difference between cardioid and hypercardioid?
Both pick up sound mainly from the front. Hypercardioid is narrower than cardioid, so it takes in less from the sides and rear. The AT2040 in this guide is hypercardioid, while the SM7dB, SL40X and PodMic are cardioid.
Do I need a preamp for a dynamic microphone?
A dynamic microphone connects to an interface or mixer, which supplies the gain. The SM7dB has a built-in preamp with +18 dB or +28 dB of gain, so it drives an interface without a separate inline preamp.
Ranked dynamic microphones lists
More how-to guides
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